Obesity is a worldwide public health problem and recent work has suggested that alterations in maternal nutritional status may increase the risk of becoming obese. Epidemiological data have shown that maternal under-nutrition can lead to intrauterine growth retardation with long-term consequences to offspring including hypertension, cardiovascular disease, type 2 diabetes and obesity. Evidence is now emerging that maternal over-nutrition may have similar long-term consequences. Specifically, maternal consumption of a high fat diet, characteristic of the modern day Western lifestyle, has been shown to lead to metabolic disorders such as obesity and insulin resistance in offspring. The mechanisms mediating the consequences of maternal over-nutrition are not well understood. The overall goal of this proposal is to characterize the short- and long-term effects of maternal consumption of a high fat diet and resulting obesity in a polygenic diet induced rat model of obesity. The specific experiments address numerous aspects of the RFA in that they will: 1) characterize an animal model appropriate for the study of metabolic consequences of maternal high fat diet consumption and obesity, 2) define critical periods of susceptibility to metabolic perturbations on neural pathways involved in energy balance and 3) investigate the role of epigenetic changes as mediating mechanisms. The specific aims are: 1) To determine the developmental time course of behavioral and endocrine alterations resulting from maternal high fat diet consumption in obesity prone Sprague Dawley rats, 2) To test the hypothesis that maternal consumption of high fat diet produces alterations in hypothalamic neuropeptide signaling systems involved in energy balance that bias the developing pups toward obesity and metabolic disturbances, and 3) To determine whether high fat diet results in obesity and metabolic disturbances in offspring through epigenetic modifications. We hypothesize that genes that are critical to energy homeostasis are subject to regulation by DNA methylation and are differentially methylated in response to exposure to maternal high fat diet consumption and obesity. The results of these experiments will enhance our understanding of the etiology of obesity and metabolic disease ultimately allowing the development of rational clinical interventions for such conditions.